Screw-holding screw driver



p -29, 1964 P. H. ALLEN 3,150,699

, SCREW-HOLDING SCREW DRIVER Filed 001:. 3. 1960 INVENTOR. PHIL/P H- ALLEN ATTORNEYS United States Patent 3,150,699 SCREW-HOLDING SCREW DRIVER Phiiip H. Allen, Saratoga, Califi, assignor to HJJ. Company, Oakland, Calif., a partnership Filed Oct. 3, 1960, Ser. No. 60,169 7 Claims. (Cl. 14550) The present invention relates to screw-holding screw drivers and is concerned more particularly with an improved screwdriver of the above character having a simple and effective anchor for the bits of the bit structure on the rod of such structure.

It is a general object of the invention to provide an improved screw-holding screwdriver.

It is another object of the invention to provide a screwholding driver of the type having receding bit structures with expanding points for engaging the slot of the screw with novel means for attaching the respective bits to the rod forming part of the bit structure.

Other objects and advantages of the invention will be apparent from the following description of a preferred embodiment thereof, made with reference to the attached drawings, in which:

FIG. 1 is a fragmentary longitudinal sectional view through the screwdriver with certain parts shown in elevation and with the tube and out-expanding pin shown in section;

FIG. 2 is a perspective exploded view with fragmentary parts of the two bits and the rod shown in cooperative relation;

FIG. 3 is a fragmentary elevational view of the rod and bits in assembled position;

FIG. 4 is a fragmentary view taken in a plane indicated by the line 4-4 in FIG. 3 but with the rod shown in elevation;

FIG. 5 is a fragmentary transverse sectional view taken in a plane indicated by the line 5-5 in FIG. 3;

FIG. 6 is an enlarged perspective view of the pin locating ferrule illustrated in FIG. 1, the ferrule being partially broken away to illustrate details of construction;

FIG. 7 is a fragmentary sectional view similar to FIG. 1 illustrating a tool employing a modified form of ferrule.

Referring to FIG. 1 there is shown a screw-holding screwdriver which comprises a tubular handle 10, a rod 11 slidably and rotatably mounted in the handle, and having reduced end portion 11a forming a seat for respective bits or points 12 of a bit structure comprising the rod and the bits. The reduced end portion 11a is separated from the full diameter portion of the rod 11 by an annular recess or groove 13, one side wall of which is formed at the end of the full diameter rod portion and the other side wall of which is formed at the adjacent end of the end portion 11a of reduced diameter.

Intermediate the ends of each bit or point 12 there are provided respective cam surfaces 12b which gradually converge with the similar opposed cam surfaces toward the bit end of the tool. The respective bits terminate in flattened opposite engaged ends 120 for reception in the slot of the screw and for expanding therein.

To carry out the expanding action of the opposite ends 120 of the bits, there is provided a camming pin 15 which is mounted on the handle of the tool by means of a ferrule 16. The ferrule preferably has a light press-fit over the outside of the handle and is provided with a pair of ears 17 which may be bent inwardly after installation of the ferrule on the handle to engage in opposite apertures 18 of the handle. The end of the ferrule opposite from the cars 17 has a rolled end portion 19 which is placed in overlapping relation with the adjacent wall of the ferrule and is in abutting relation with the end of the handle 10. At diametrically opposite locations the bent over end or Patented Sept. 29, 1964 flange 19 is provided with respective recesses or notches 21 which receive the ends of the pin 15. By providing the mounting ferrule for the pin 15, stresses are removed from the handle 10 in the camming of the bits apart and also in the matter of resisting twisting stresses during the turning action of the tool in placing a screw. This removes the limitation as to the material of which the handle 10 can be made so that it can be made of a soft material such as aluminum or plastic.

In order to effectively hold the bits or points 12 for movement with the rod 11, the shank portion of each bit is half tublar in form and has adjacent its butt end respective slits or notches 22 to provide opposite ears 23 which are formed inwardly from the half tubular form to seat in the annular groove 13 so as to lock or anchor the bits to the rod 11, and when placed in the handle 10 to lock them on the rod 11.

Referring to FIG. 7 there is shown a modified form of the tool wherein the handle 30 is recessed adjacent an end to receive a cylindrical or tubular ferrule 31 having respective opposed apertures 32 to receive the bit expanding pin 33, the ends of the pin being encompassed by the tubular handle 30. The tubular ferrule 31 is preferably formed as a punch press part from a suitable spring material having the apertures 32 appropriately located to be diametrically opposite when the rectangular sheet is in cylindrical form. Preferably, a small slot 31a will be left between the ends of the piece forming the tubular ferrule to allow installation past an overhanging annular lip 30a at the end of the tube. This overhanging lip 30a serves to seat the ferrule 31 within the handle and to resist impact of the rod 11 against the pin 33.

In operation the screw to be held is placed with the slot embracing the points and the bit structure is caused to recede within the handle whereby the pin 15 causes spreading of the points apart into gripping relation within the screw slot.

While I have shown and described a preferred form of the invention, it is obvious that the invention is capable of variations and modification from the form shown so that its scope should be limited only by the scope of the claims appended hereto.

I claim:

1. In a screw-holding driver of the type having a tubular handle, a bit structure slidably mounted within said tubular handle and comprising a rod and a pair of opposed similar bits engaged therewith, said bits terminating in adjacent ends adapted to engage within the slot of a screw, and a pin carried by said handle and disposed between said bits to effect expanding movement thereof upon receding movement of said bit structure with respect to said handle; the improvement which comprises said rod having an annular groove defined on each side by walls extending perpendicular to the axis thereof, and further characterized by each bit being formed symmetrically about its longitudinal center line and having a half tubular shank for embracing said rod, the edge portions of each bit shank being slit at a point spaced from the butt end of the bit at right angles to the longitudinal axis of said bit to form respective anchoring ears with one side edge of each ear forming a portion of an end wall of the extreme butt end of the bit, and said ears being bent inwardly to seat in said annular groove on opposite sides thereof.

2. In a screw-holding driver of the type having a tubular handle, a bit structure slidably mounted within said tubular handle and comprising a rod and a pair of opposed similar bits engaged therewith, said bits terminating in adjacent ends adapted to engage within the slot of a screw, and a pin carried by said handle and disposed between said bits to effect expanding movement thereof upon receding movement of said bit structure with respect to said handle; the improvement which comprises said rod having a bit seating portion of reduced diameter at the screw-holding end of said screwdriver, said bit seating portion being joined to the portion of full diameter of said rod by an annular groove defined on each side by walls extending perpendicular to the axis thereof, and further characterized in that each bit is symmetrical about its longitudinal center line and each bit has a half tubular shank for embracing said rod, the edge portions of each bit shank being slit at a point spaced from the butt end of the bit at right angles to the longitudinal axis of said bit to form respective anchoring ears with one side edge of each ear forming a portion of an end wall of the extreme butt end of the bit, and said ears being bent inwardly to seat in said annular groove on opposite sides thereof.

3. In a screw-holding driver of the type having a tubular handle, a bit structure slidably mounted within said tubular handle and comprising a rod and a pair of opposed similar bits engaged therewith, said bits terminating in adjacent ends adapted to engage within the slot of a screw, and a camming pin carried by said handle and disposed between said bits to eifeet expanding movement thereof upon receding movement of said bit structure with respect to said handle; the improvement which comprises a pin-mounting ferrule engaged with the end of said tubular handle adjacent to said bits, said handle including means for securing said ferrule against axial movement with respect to said tubular handle, and camming pin 10- cating means in said ferrule to hold the pin in fixed relation to said handle and with said pin extending between said bits.

4. In a screw-holding driver as recited in claim 3 in which said ferrule has one end formed inwardly in overlapping relation with a wall of said ferrule, and said one end has diametrically opposed recesses adjacent to the end surface of the handle to provide a pin-seating or locating means by the cooperation of said ferrule and said handle, said handle has opposite apertures therein adjacent the end of said handle and said ferrule has ears extending into said apertures to locate said ferrule on said handle.

5. A screw-holding driver as recited in claim 3, in which said ferrule is seated within said handle and has opposed pin receiving recesses.

6. In a screw-holding driver as recited in claim 3 in which said ferrule is formed of a sheet of resilient material having an opposed pin receiving recess when installed, said sheet having two edges parallel to and spaced from one another in the direction of the longitudinal extent of said tubular handle, and two other edges adjacent to one another and parallel to one another in a direction parallel to the longitudinal extent of said tubular handle.

7. In a screw-holding driver as recited in claim 6 in which said handle has a ferrule receiving recess adjacent one end, the said one end of said handle terminating in an inwardly directed annular lip overlying the end of the ferrule in retaining relationship therewith, said recess and said tubular handle, and two other edges adjacent to one movement with respect to said handle.

References Cited in the file of this patent UNITED STATES PATENTS 1,394,438 Mills Oct. 18, 1921 1,886,155 Bohlman Nov. 1, 1932 2,313,710 Gemrnell Mar. 9, 1943 2,404,427 Bloomfield July 23, 1946 

1. IN A SCREW-HOLDING DRIVER OF THE TYPE HAVING A TUBULAR HANDLE, A BIT STRUCTURE SLIDABLY MOUNTED WITHIN SAID TUBULAR HANDLE AND COMPRISING A ROD AND A PAIR OF OPPOSED SIMILAR BITS ENGAGED THEREWITH, SAID BITS TERMINATING IN ADJACENT ENDS ADAPTED TO ENGAGE WITHIN THE SLOT OF A SCREW, AND A PIN CARRIED BY SAID HANDLE AND DISPOSED BETWEEN SAID BITS TO EFFECT EXPANDING MOVEMENT THEREOF UPON RECEDING MOVEMENT OF SAID BIT STRUCTURE WITH RESPECT TO SAID HANDLE; THE IMPROVEMENT WHICH COMPRISES SAID ROD HAVING AN ANNULAR GROOVE DEFINED ON EACH SIDE BY WALLS EXTENDING PERPENDICULAR TO THE AXIS THEREOF, AND FURTHER CHARACTERIZED BY EACH BIT BEING FORMED SYMMETRICALLY ABOUT ITS LONGITUDINAL CENTER LINE AND HAVING A HALF TUBULAR SHANK FOR EMBRACING SAID ROD, THE EDGE PORTIONS OF EACH BIT SHANK BEING SLIT AT A POINT SPACED FROM THE BUTT END OF THE BIT AT RIGHT ANGLES TO THE LONGITUDINAL AXIS OF SAID BIT TO FORM RESPECTIVE ANCHORING EARS WITH ONE SIDE EDGE OF EACH EAR FORMING A PORTION OF AN END WALL OF THE EXTREME BUTT END OF THE BIT, AND SAID EARS BEING BENT INWARDLY TO SEAT IN SAID ANNULAR GROOVE ON OPPOSITE SIDES THEREOF. 